Análise da deposição de revestimentos de aço inoxidável AWS 309L por MIG em substrato de aço carbono

Abstract

This work is a study about the analysis of parameters which allow the deposition of AWS 309L stainless steel plates in carbon steel using MIG process. This work shows the importance of coating processes and their use in the market, showing the growth of its use over time and citing the tendency to use to optimize its parameters. Using metallographic analysis, we analyzed what the influence of the voltage, wire feed speed and welding speed have on the morphology of the weld beads, seeking to maximize the area covered with each pass of the weld bead. Analyses of the economic characteristics of each combination of parameters are made, taking account with the rate of deposition, the fusion rate and yield. Defining the best combination of parameters, it has the overlap of strings that optimizes the process, reducing the need for subsequent manufacturing processes to the coating. At the end of this work, it was concluded that the increase of welding voltage causes an increase in width and reduction in height of the bead, creating a more adequate to process geometry. The increase in the feed rate decreases the wire width and increasing the height of the bead. It was also noted that the increase of welding speed resulted in the increase of the bead width and no significant changes in height. By analyzing the overlap, it was concluded that over 40 % overlap of the beads, the coating becomes uneven and excessive heights, and a smaller area coated with the same amount of passes. By reducing the overlap to less than 20%, the coating also appears to be irregular, causing many flaws. Combining the best results, it was concluded that, using 27 V voltage, welding speed 26 cm / min, the wire feed speed of 6 m / min, and the overlap of 30 % was achieved for the best outcome coating.